If you have lived in the house for less than 12 months you may have to pay CGT on whatever profit your house has made since you bought it - even if you move to another house.
If the house is in both names/ you are married then yes you do get 2 lots of tax relief... 8K each as an allowance per year (so, dur, 16K) and on top of that you calculate tax according to income. If you both pay higher tax rate then you will have to pay 40% CGT. However if neither/one of you pays lower rate tax then whatever is left to get to higher tax rate (approx 60K per annum) is charged lower rate. All above that goes to higher rate.
Not a lawyer or an accountant, but as far as I know no capital gains tax is payable on your main residence.
If it's a BTL then capital gains tax is payable. Not sure what the exact threshold is for CGT, but in region of £7K. It might depend on how you owned the property (ie. joint tenants or tenants in common) and who put what proportion of the money up, but my understanding is that you would each get a CGT allowance, so between you you could make c. £14K capital gains before any tax became payable.
Yeah, sorry... forgot to mention that. I assumed you had more than one property. If you have more than one then you have to live in the 'primary residence' for a minimum 12 months. If you are selling a secondary residence you will be taxed whatever.
if your house is mortgaged at all, transferring to children is usually a no no.
And then to get it back again is a major hassle. Conflicts of interest left right and centre
You can set up a trust which can include property which can circumvent some tax issues, but this is usually applicable for a number of properties and wealth...
If you are simply selling your house and buying again then I did not think CGT was payable though.